Sleeve joint for connecting steel inserts in steel-concrete construction

ABSTRACT

This invention relates to a sleeve joint for connecting steel inserts in steel-concrete construction which comprises shaped metal bodies secured to the ends of the inserts to be connected, sleeve means enclosing at least part of both of the shaped metal bodies and being of larger diameter than said bodies, and aluminothermically produced metal in the space between the sleeve means and said bodies.

287/76, 82, 81, 80, 20.2; 52/726, 722; 164/98, 108, 110, 53, DIG.l2,ll1, 334; 285/284, 291, 292, 297; 29/460 0 Umted States Patent 11513,638,978 Guntermann 1 Feb. 1, 1972 [54] SLEEVE JOINT FOR CONNECTING[56] References Cited STEEL lNSERTS IN STEEL-CONCRETE CONSTRUCTIONUNITED STATES PATENTS 1,689,281 I0 1928 l [721 Gumermanm Essemsteele,Germany 2,515,191 7/1950 5325mm et al. 16 51 622 [73] Ass1gnee:fizzltlro-Thermit G.m.b.H., Essen, Ger- FOREIGN PATENTS OR APPLICATIONS[22] Filed: Dem 812,251 2/1937 France ..l64/l08 [211 Appl. No.: 692,526Primary Examiner-David J. Williamowsky Assistant ExaminerWayne L. Shedd[30] Foreign Application Priority Data Atmmey james 5 Bryan Dec. 24,1966 Germany ..D 34794 1 ABSTRACT This invention relates to a sleevejoint for connecting steel in- [52] U.S.Cl ..287/l08, 52/726, l64/53,Sens in steebconcrete construction which comprises shaped 164/108164/110 164/111 l64/DIG- 12 metal bodies secured to the ends of theinserts to be con- [51] IIILCI ..Fl6b 7/00 acted, Sleeve means enclosingat least part f both of the [58] Field of Search ..287/108, 127 E, 77,78, 75,

shaped metal bodies and being of larger diameter than said bodies, andaluminothermically produced metal in the space between the sleeve meansand said bodies.

10 Claims, 4 Drawing Figures PATENIEO FEB 1 I97? sum 1' or 2 HANSGUNTERMANN BY 9 Z ATTORNEY INVENTOR HANS GUNTERMA NN BY W ATTORNEYSLEEVE JOINT FOR CONNECTING STEEL INSERTS IN STEEL-CONCRETE CONSTRUCTIONSUMMARY OF THE DISCLOSURE The present invention relates to a sleevejoint for connecting steel inserts, preferably reinforcing steels, usedin steelconcrete construction, and more particularly relates toconnecting prefabricated structural steel-concrete elements, by using asleeve and aluminothermically produced metal.

In steel-concrete construction it is known to connectconcrete-reinforcing ribbed steels by means of sleeve oints. This iseffected, for example, by enclosing the ends of the profiled steelinserts subject to stress with a steel pipe joint which is internallyprofiled in a threadlike manner, and by filling the cavities between thesteel ends and the sleeves with aluminothermically produced metal,preferably steel.

This butt joint requires that the steel inserts have correspondinglyprofiled surfaces and be so designed with respect to the quality thereofthat their physical properties are not impaired by heat, such as will beproduced when molten aluminothermically produced metal is poured intothe sleeve.

Also employed, however, for the construction of buildings fromsteel-concrete are steel inserts which do not have a profile suitablefor the sleeve joint, or, for example, so-called reinforcing steelswhose physical properties are considerably impaired by the subsequentaction of heat, so that the sleeve joint it not suitable as a connectionfor such steel inserts.

lt is known in the art to connect threaded bracing or clamping memberswith the aid of threaded sleeves. This, however, can be accomplishedonly if the bracing members are movable to a large extent. In the caseof prefabricated structural concrete elements, for example, the ends ofthe reinforcing rods projecting at the end faces can not be joined inthis fashion since neither the installation of the reinforcing rods, northe construction and assembly of the finished parts is withouttolerances, which latter must be compensated for in the joint.

The present invention provides a means for connecting. in a thermallyunaffected manner, reinforcing steels of finished concrete parts whichare, more particularly, not in precise alignment with each other, aswell as steel inserts which do not have a profile suitable for the knownsleeve joint, in a manner such that the tractive forces and pressurescan be transmitted free from slippage.

The present invention provides a sleeve joint in which shaped steelbodies, preferably being profiled at the surfaces thereof in athreadlike manner, either each enclose one end of the steel reinforcingrods in the form of a sleeve, or are connected therewith at the endfaces thereof. The shaped steel bodies, in turn, are enclosed at adistance by an internally profiled steel pipe sleeve, and the cavityformed bet een the sleeve and the steel bodies is filled withaluminothermically produced metal, preferably steel.

ln a preferred embodiment of the sleeve joint of the present invention,the externally profiled shaped steel bodies are provided with internalthreads and are screwed onto the ends of steel rods having correspondingexternal threads.

ln a further embodiment of the present invention, one end of a steel rodis connected with an externally profiled shaped steel body, the oppositeend of the steel rod is connected with an internally profiled shapedsteel body being simultaneously constructed as a sleeve, in which casethe internally profiled body will enclose with a certain distance or gapthe externally profiled body, and the cavity thus produced is filledwith aluminothermically produced metal, preferably steel.

The sleeve joint of the present invention is particularly suitable forconnecting the reinforcing steels of finished concrete elements, suchas, for example, track mounting or supporting plates, where tighteningor adjusting nuts, for example, are screwed onto the ends of thereinforcing steel and serve for transmitting the elastic forces into theanchoring structure. These nuts enclose, for example, the ends of thetie rods in the full length thereof with which they project beyond theend face of the finished parts or elements. In the present invention,these tightening nuts, which heretofore had a smooth outer surface, areprovided with an external profile which advantageously consists of acrude thread.

The present invention is not limited, however, to adjusting ortightening nuts of this type but is directed generally to all caseswhere steel inserts, particularly reinforcing steel ends, must beprotected against the action of heat which would adversely affect thephysical properties of this material, and where a suitable profilerequired for the sleeve joint must be provided for later.

In the present invention, the truss forces are thus transmitted-with theinterposition of profiled steel bodies which enclose the ends of thesteel rods and/or are connected therewith:at the end faces thereofeither mechanically or by welding, using aluminothermically producedmetal, preferably steelthrough the steel pipe joint, i.e., by means ofthe toothed construction between the shaped steel bodies connected withthe steel inserts, the casting metal, and the sleeve.

The present invention will be further illustrated by reference to theaccompanying drawings wherein FIG. lis a view in cross section through asleeve joint showing the shaped steel elements 1 and 2 being externallyprofiled in a threadlike manner, the tie or truss rods 3 and 4, theinternally profiled steel pipe joint 5 with the passage 6 and thecasting metal 7;

FIG. 2 is a view in cross section through a sleeve joint showing theshaped steel elements 10 and 11 mounted at the end faces thereof on therod ends 8 and 9, the sleeve 12, the passage 13 and the casting metal14;

FIG. 3 is a view in cross section through a sleeve joint showing theshaped steel elements 16 and 18 mounted on the ends of the steel insertsl5 and 17, the shaped element 18, simultaneously being constructed as asleeve, the passage 19, and the casting metal 20; and

FIG. 4 is a view in cross section through a sleeve joint according toFIG. 1 employed for purposes of connecting prefabricated prestressedconcrete plates 21 and 22, and showing a reaction crucible 23 attachedthereto for the aluminothermic production of the casting metal.

Referring to FIG. 1, the shaped steel elements 1 and 2, being externallyprofiled in a threadlike manner, are screwed onto the ends of thereinforcing steels 3 and 4. The shaped steel elements 1 and 2 areenclosed at a distance by an internally profiled steel pipe joint 5, andthe joint or sleeve 5 includes a passage 6 through whichaluminothermically produced 'metal 7, preferably steel, may be pouredin.

In FlG. 2, the sleeve joint of the invention is illustrated as it isused for steel inserts or rods which, for example, do not have a profilesuitable for the sleeve joint. In the embodiment shown, the shaped steelelements 10 and 11 are connected at the end faces thereof with the endsof the steel inserts 8 and 9. The shaped steel elements 10 and 11 arescrewed, in this case, onto external threads on the ends of the steelinserts 8 and 9. For this purpose, the shaped steel elements 10 and 11are provided in each case at one end thereof with a bore having acorresponding internal thread, and at the other end thereof with anexternal profile. The externally profiled ends of the shaped steelmembers are enclosed by a steel pipe joint 12 including a passage 13.Reference numeral 14 identifies the aluminothermically produced castingmetal, preferably steel.

The embodiment according to FIG. 3 is a sleeve joint in which the end ofthe steel insert 15 is connected with an externally profiled shapedsteel element 16, whereas the end of the steel insert 17 is enclosed bya shaped steel element 18 having a cavity therein so that one end of theelement 18 constitutes an internally profiled sleeve. Reference numeral19 identifies the passage for the aluminothermically produced castingmetal 20, preferably steel.

FIG. 4 illustrates, in further detail, how a sleeve joint according toFIG. 1 is made. For example, prefabricated trackmounting plates 21 and22, through the longitudinal axes of which extend the tie or truss rods3 and 4 being threaded at least at the ends thereof, are intended to beconnected with each other with a traction and pressure resistantconnection of the clamping members being desired. In the course of ahotrolling process, these reinforcing steels are provided with ribportions in the form of a helix and also form a thread suitable forscrewing a nut thereon.

The reinforcing members 3 and 4 transmit the tensional forces thereof tothe concrete by way of the anchoring shells 24. Screwed onto the ends ofthe bracing rods 3 and 4 which project beyond the anchoring shells 24are the shaped steel elements in the form of long nuts 1 and 2 whichmultaneously contribute to introducing the tensional forces into theanchoring. These nuts 1 and 2 enclose the bracing rod ends 3 and 4 inthe full length thereof with which they project beyond the end faces ofthe finished parts 21 and 22. They are provided with a profile 25.

Slid over the ends of the nuts 1 and 2 is a steel pipe joint or sleeve 5whose inside diameter is somewhat larger than the outer diameter of thenuts 1 and 2 so that it is possible to also compensate for differencesin alignment within certain limits, which differences could arise whenthe tie or bracing rods to be interconnected are not in alignment witheach other. The sleeve 5 also is longer than is necessary for achievinga firm connection with the nuts 1 and 2 so as to be adapted to absorblongitudinal differences at the same time. Also, the sleeve 5 isprovided at the inside thereof with a profile 26. The sleeve 5 furtherincludes an upwardly directed passage 6 which serves for mounting acrucible 23 thereon having a reaction chamber 27 for receiving thealuminothermic mixture 28 which produces the casting metal.

The crucible 23 has an outlet 29 which is closed off by inlaid metalplatelets 30. The end-face openings of the sleeve 5 are closed off, forexample, by means of asbestos 31. In this case, the sleeve 5 issimultaneously enclosed with a collar 32 of asbestos in order to preventany possible melting through of the sleeve. Filled into the reactionchamber 27 of the crucible 23, after inserting the closure 30, is thealuminothermic mixture 28 which consists, for the purpose of producingsteel, of iron oxide, aluminum and alloying elements. The mixture isthen ignited in the form of points with an exothermic reaction thusbeing initiated, at which time the aluminum is converted into aluminumoxide and steel is liberated which will be deposited in the lower partof the reaction chamber 27. The molten aluminothermically produced steelmelts through the closure 30 and runs through the outlet 29 and thepassage 6 into the cavity of the sleeve 5 where it fills the cavity,formed by the sleeve 5 and the nuts 1 and 2, with steel 7.

The nuts 1 and 2 protect, at that time, the bracing members 3 and 4,being susceptible to the action of heat, so they will not be alteredwith respect to the physical properties thereof.

It will be obvious to those skilled in the art that many modificationsmay be made within the scope of the present invention without departingfrom the spirit thereof, and the invention includes all suchmodifications.

What is claimed is:

1. A sleeve joint for connecting steel inserts in steelconcreteconstruction which comprises shaped metal bodies threaded onto the endsof the inserts to be connected and surrounding and enclosing the majorportion of the ends of said inserts to isolate them from the heat ofaluminothermically produced metal, sleeve means enclosing at least partof both of the shaped metal bodies and being of larger diameter thansaid bodies, and aluminothermically produced metal in the space betweenthe sleeve means and said bodies.

2. A joint according to claim 1 in which the shaped metal bodies aresteel sleeves threaded onto the inserts.

3. A joint according to claim 1 in which the shaped metal bodies aresteel nuts threaded onto the inserts.

4. A joint according to claim 1 in which the shaped metal bodies haveexternal profiles thereon.

5. A joint according to claim 4 in which the external profiles are inthe form of threads.

6. A joint according to claim 1 in which the sleeve means has aninternal profile. I

7. A oint according to claim 6 in which the sleeve means 15 fabricatedfrom steel.

8. Ajoint according to claim 1 in which the aluminothermically producedmetal is steel.

9. A sleeve joint for connecting steel inserts in steelconcreteconstruction which comprises a shaped metal body threaded onto the endof one of the inserts to be connected and surrounding and enclosing themajor portion of the end of said insert to isolate it from the heat ofaluminothermically produced metal, sleeve means threaded directly at oneend thereof onto the end of the other insert to be connected andenclosing at the other end thereof at least part of the shaped metalbody and being of larger diameter than said body, and aluminothermicallyproduced metal in the space between the sleeve means and said body.

10. Ajoint according to claim 9 in which the sleeve means is fabricatedfrom steel.

1. A sleeve joint for connecting steel inserts in steel-concreteconstruction which comprises shaped metal bodies threaded onto the endsof the inserts to be connected and surrounding and enclosing the majorportion of the ends of said inserts to isolate them from the heat ofaluminothermically produced metal, sleeve means enclosing at least partof both of the shaped metal bodies and being of larger diameter thansaid bodies, and aluminothermically produced metal in the space betweenthe sleeve means and said bodies.
 2. A joint according to claim 1 inwhich the shaped metal bodies are steel sleeves threaded onto theinserts.
 3. A joint according to claim 1 in which the shaped metalbodies are steel nuts threaded onto the inserts.
 4. A joint according toclaim 1 in which the shaped metal bodies have external profiles thereon.5. A joint according to claim 4 in which the external profiles are inthe form of threads.
 6. A joint according to claim 1 in which the sleevemeans has an internal profile.
 7. A joint according to claim 6 in whichthe sleeve means is fabricated from steel.
 8. A joint according to claim1 in which the aluminothermically produced metal is steel.
 9. A sleevejoint for connecting steel inserts in steel-concrete construction whichcomprises a shaped metal body threaded onto the end of one of theinserts to be connected and surrounding and enclosing the major portionof the end of said insert to isolate it from the heat ofaluminothermically produced metal, sleeve means threaded directly at oneend thereof onto the end of the other insert to be connected andenclosing at the other end thereof at least part of the shaped metalbody and being of larger diameter than said body, and aluminothermicallyproduced metal in the space between the sleeve means and said body. 10.A joint according to claim 9 in which the sleeve means is fabricatedfrom steel.